Behind-the-lens filter and mask adapter



April 18, 1950 J. DE LANAUZE BE IIND-THE-LENS FILTER AND MASK ADAPTERFiled Oct. 17, 1947 1724492257 Jac zzea aiefazzaaze Illll I llllllRatented Apr. 18, 1950 UNITED s Par-am caries 3mm a, mum; briamuonmiomsmmritlitirtrod bcitbei-iv, lsi'ii sehafmf'laditts l liliainia.

The present invention re'iiites'to" a-"filterfol cameras, and, morepartleuim -sfilier reacts with turret cameras and ad'a'pt'ed'to befitted behind the lens thereof.

In present day photography, filters wane come necessary units of'eduipmeiltto the craman who carries out hisworli' bride! W '9 varyinglight conditions. In fact, expense has shown photographers thedesirabilityfoffii rying with them a set of filterscapable'or' W iZingthe different cbiou'rsbf light-which icmiiht be expected to encounter.

This problem is iurther complicated, in motion picture photography, bythe use of turret cameras, in which several lenses each appropriate fora different type criteria may be mounted on a rotatable turret,wnereupontbc icnsrdesired for any type of work may be tummy brought intoposition in front of the camera gate. in using such camerasin the'past,therefore, it has often been found fiecessaryto three sets of filters ormore, one set for esn lcns provided. multiplication o; the number offilters required is what the present invention contemplates avoiding,and this without any decreaoe'in fii'mcielfiy df U18 camera.

The method by which the present invention plans to circumvent the abovedifllculties, is by providing a filter set in an appropriate holderwhich may be fitted directly into the gate of the camera underneath thebase plate of the turret. By disposing an appropriate filter in such aposition, it will serve adequately for any of the lenses disposed uponthe turret, and only single set of filters will be necessary. Moreover,a suitably designed filter so disposed will not alter the focusingcharacteristics of the camera lens.

The main object, then, of the present inventiorv is to provide a filterand a suitable holder therefor, which may be fitted directly in the gateof a turret camera.

Another important object resides in the provision of a smera filter ofthe character described wh'lh is easily and quickly insertihlc in orremo [able from the gate of a camera.

And an ,ther object resides in the provision of a camera filter of thecharacter described which will not alter the focusing characteristics ofthe camera.

Other objects and advantages will become apparent, or be further pointedout, in the description to follow.

(Cl. OM15) 1 shcws'a-pel'spect'ive-view or the fits? aric npm mkhre'*shows a-sebtiodalong the fih'erii shows in elevatldn view of a' fllteiaccording to the invention in theprocessor being W sbw s i Mtme imere";'shbws a nemesisys'eb'tlonai 'laii oi'tlieto'the-invfint'idn fi 3intotliegatepiacamera.

Relfeiimgjiidw to the drawfi'i'ff'whi rein same rererese "characterspaiis "th'roiighout," the filter according the in vention isindicatedgenerally by h aiidwill he fitteddntc the Q'site Goia-eiiiera--C,"the latter ofwhich" T is' themes pistef a'wimna eaacosedsatanic-lessees It the :g'ab -G is seams? Caesar inshabe, and 1s*aepressedsameivnat from the front face of the fcamerafofi'behindthefiblate Phi-the tu ret. it-is ih'to tiiis de m unt the or theinventifiii lateness-stem.

"me iilt'er lai -therefore bieierably circular-in. shape and of somewhatsmaller diameter than the frame of the gate of the camera. In accordancewith the invention, the filter proper will consist of a thin film orwindow i f gelatin or the like, such material being preferably usedowing to its extremely low defractive properties, thus eliminating anypossibility of changing the focusing characteristics of the camera.

- The holder of the filter will also be circular in shape consisting oftwo circumferential rims i3. between which the gelatin film 5 is fitted,and the flange I directed at right angles to the plane of the filmaround the perimeter thereof and integral with the rims.

The outside diameter of flange I will be such that this flange will fitcomfortably into the depression formed by the gate G of the camera. Whenthus fitted into the camera, the gelatin fllmntainedbytherimiwillbedisposed across the gate of the camera.

In order that the flange may be held more securely in the gate of thecamera, suitable proiections may be provided in the outside surfacethereof so that, even with a loose strip between flange and gate edges,the filter will be held securely. Thus in Figure l, the flange is shownformed with three, angularly disposed, cut-outprojections in the outersurface thereof. Ex-

an example, and for purposes of illustrasunning the left extremity ofFigure 2, it is seen Figure 4 shows the filter disposed in place in thegate of a camera with the base plate of the band of suitable dimensionsto be fitted in said gate, a light-modifyin fi m adapted to transmitlight fitted across said band. struck projections on said band adaptedto hold the latter in the gate by frictional engagement and a tabprojecting from said band to aid in releasing the latter from the gate.

2. A filter for cameras having a lens gate, com- P1 51 18 band adaptedto be removably fltted in said gate, interior rims around said band, afilm of light-transmitting material :secured across said band betweensaid rims, more than one segment of the perimeter of said band turretand a lens carried thereby rotated into place in operative position.

It will be clear that, in place of a light=filtering and transmittingfilm, a film adapted to pass light in various patterns might be fittedin the holder, and hence serve as a mask. Thus a substantially opaquefilm having a transparent porticn simulating a keyhole, for instance,might be fitted to the holder, and any resultant pictures would appearto have been taken through a keyhole. Any other (it sired pattern mightbe employed and a corresponding efl'ect obtained.

Obviously from the foregoing, the present invention fulfills theobjectives hcreinb fore set forth. A set of filters so constructed maybe easily and quickly inserted into place or removed from the gate ofthe camera, and will serve adequateiy for any of the lenses brought intoplace in front thereof. Moreover, the provision of the projectingportion 8 of the flange and the tab 9 insure that a snug fit will bepreserved in the gate of the camera, and that the filter will not become stuck in place. I

It will be understood that I do not limit myself to any particularshapeor size of parts component in this invention but rather thatvarious changes therein may be made without departing from the spirit ofthe invention or the scope of the subjoined claims.

L ving thus described my invention, I claim: 1. The combination with acamera having a lens gate and a turre lens mount, of a filter engageablein said gate, said filter comprising a -be'n't outwardly therefrom forthe purpose of frictionally engagin said gate, and a tab projecting froma portion of one edge of the perimeter of the band to aid in theremoving thereof from the gate.

3.: As an article of manufacture, a behind-thelens filter for camerashaving a lens turret and gate, said filter comprising a circular bandadapted to fit in said gate, a film of light-transmittin and modifyingmaterial fitted across said band, projections on said band comprisingmore than one portion of the perimeter of the band separated from therest thereof and bent outwardly therefrom; whereby said projections areadapted to hold the filter in the gate by frictional engagement with thelatter, and a tab projecting from an edge of the perimeter of the bandto aid in the releasing thereof from engagement with the gate.

,1 JACQUES n1: LANAUZE.

REFERENCES orrnn The following references are of record in the fllei ofthis patent:

UNITED STATES PATENTS 234.474 Great Britain Aug. 16, 1925

